commit 8473607bcfef62fd8f6bb98b27807bbfce30a81a
author David Woodhouse <dwmw@amazon.co.uk> Wed Oct 11 23:50:02 2023 +0100
committer David Woodhouse <dwmw@amazon.co.uk> Tue Nov 07 08:54:20 2023 +0000
tree 09771965e27ba579deebbe7866adf1aeb8a1c1bf
parent 8ac98aeddaac1778e7c725609f1fd5eaa38e2285

i386/xen: advertise XEN_HVM_CPUID_UPCALL_VECTOR in CPUID

This will allow Linux guests (since v6.0) to use the per-vCPU upcall
vector delivered as MSI through the local APIC.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>

target/i386/kvm/kvm.c

diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 770e81d..11b8177 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -1837,6 +1837,10 @@
                 c->eax |= XEN_HVM_CPUID_VCPU_ID_PRESENT;
                 c->ebx = cs->cpu_index;
             }
+
+            if (cs->kvm_state->xen_version >= XEN_VERSION(4, 17)) {
+                c->eax |= XEN_HVM_CPUID_UPCALL_VECTOR;
+            }
         }
 
         r = kvm_xen_init_vcpu(cs);